1. Implement a virtual ranking/points system
Users should be able to earn points and rank up by posting and starting discussions. This feature will incentivize users to post more frequently and make the community more active.
2. Implement a virtual shop for the incentive points
Following as a component of the first suggestion, the points earned by the users could be spent on unlocking more features on their profile.
3. Implement badges
Badges can accumulate and is displayed on the user's profile. They can be earned by completing specific tasks, such as "mention more than 100 users", or "have over 200 posts", etc.
4. Develop a leaderboard system
There should be a leaderboard showing the user with the most points earned as well as the user with the highest rank. Top 3 users for both leaderboards should receive a purpose-built badge.
5. Add more/more specific sections!
This will organize the forum and provide more topics for users to chat about.